Top rail corner piece



FIG. 1 is a perspective view of a top rail corner piece showing my design (with environment shown in phantom and not claimed as part of the invention);

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view thereof (left side view is a mirror image thereof);

FIG. 4 is a rear view thereof (right side view is a mirror image thereof); and,

FIG. 5 is a bottom view thereof. 

The ornamental design for top rail corner piece, as shown and described. 